Question: what is the point in time for vigo has population as 294997.0?
Paraphrase: When did the population in Vigo reach 294997?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q8745 p:P1082 ?s . ?s ps:P1082 ?x filter(contains(?x , '294997.0')) . ?s pq:P585 ?value}